Merge CSV files into a single file with no repeated headers

Question

I have some CSV files with the same column headers. For example

File A

header1,header2,header3
one,two,three
four,five,six

File B

Answer 1

Late here but Fuzzy-Csv (https://github.com/kayr/fuzzy-csv/) was designed just for that.

This is what the code would look like

        String csv1 = "NAME,SURNAME,AGE\n" +
                "Fred,Krueger,Unknown";

        String csv2 = "NAME,MIDDLENAME,SURNAME,AGE\n" +
                "Jason,Noname,Scarry,16";

        FuzzyCSVTable t1 = FuzzyCSVTable.parseCsv(csv1);
        FuzzyCSVTable t2 = FuzzyCSVTable.parseCsv(csv2);

        FuzzyCSVTable output = t1.mergeByColumn(t2);

        output.printTable();

Output

╔═══════╤═════════╤═════════╤════════════╗
║ NAME  │ SURNAME │ AGE     │ MIDDLENAME ║
╠═══════╪═════════╪═════════╪════════════╣
║ Fred  │ Krueger │ Unknown │ -          ║
╟───────┼─────────┼─────────┼────────────╢
║ Jason │ Scarry  │ 16      │ Noname     ║
╚═══════╧═════════╧═════════╧════════════╝

You can re-export your csv using one of the helper methods

output.write("FilePath.csv");

or 

output.toCsvString()